Diaphragm pumps are useful for transferring large volumes of liquid (e.g., water) for agricultural, construction and marine industries among others. Such pumps may efficiently transfer even mud-laden water. Typically, such pumps comprise an elastomeric diaphragm driven by a pushrod or fluctuating pressure. High volume diaphragms, particularly diaphragms with relatively high walls, risk premature failure.
As used herein, a large or high-volume diaphragm has ac. In an exemplary embodiment, a large diaphragm according to principles of the invention has a wall height of at least three inches and a wall maximum diameter at the base of at least three times the wall height, and a wall minimum diameter at the cap of about at least twice the wall height.
Wear from abrasion and repeated strain (i.e., stretching) causes cracking along the walls of high-volume diaphragms. As a high-volume diaphragm is compressed, a portion of the wall may fold over against another portion of the wall, in overlapping fashion. This overlapping, which is known as “rolling,” causes abrasion between abutting wall surfaces, while stresses concentrate at the fold line and cause stretching. Abrasion and stress compromise the wall's structural integrity, making it more susceptible to rolling, especially after repeated cycles. Eventually, the diaphragm fails, cracking or rupturing at the weakened wall.
For commercial viability, a diaphragm must perform, without failure, for a determined number of hours. The minimum number of hours is at least 600, more preferably at least 700, and ideally at least 1000 hours. Unreinforced high-volume diaphragms tend to fail after less than 700 hours of use and often less than 600 hours of use.
Others have tried reinforcing certain diaphragms with corrugations and longitudinal ribs. Such past efforts to reinforce diaphragms, while suitable for their own purpose, actually reduce the life of high-volume diaphragms. Corrugated high-volume diaphragms quickly experience rolling. Additionally, stresses concentrate along the edges of longitudinal ribs, leading to cracking.
What is needed is a reinforced high-volume diaphragm that resists rolling and endures use for at least 700 hours.
The invention is directed to overcoming one or more of the problems and solving one or more of the needs as set forth above.